Should I use 401 or 403 for authentication failures?

401 Unauthorized means the request lacks valid authentication credentials (not logged in). 403 Forbidden means the server refuses to authorize an authenticated user (logged in but not permitted). Use 401 for 'log in first', 403 for 'you can't do this'.

What is the difference between 301 and 308?

301 Moved Permanently may change the method from POST to GET on redirect (historical behavior). 308 Permanent Redirect preserves the method. Use 308 for permanent redirects where the method must not change; 301 for compatibility with older clients.

TASK

Look up the meaning of an HTTP status code

Get the category, reason phrase, and common usage for any HTTP status code (1xx-5xx).

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HTTP status codes are grouped: 1xx informational, 2xx success, 3xx redirect, 4xx client error, 5xx server error. Knowing the exact meaning (not just the category) helps debug API responses and design correct error handling.
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HTTP Status Codes →
Enter a status code (e.g. 418) or browse by category. The tool returns the reason phrase ('I'm a Teapot'), category, and common usage notes including when to use vs related codes.

Frequently asked questions

Should I use 401 or 403 for authentication failures?: 401 Unauthorized means the request lacks valid authentication credentials (not logged in). 403 Forbidden means the server refuses to authorize an authenticated user (logged in but not permitted). Use 401 for 'log in first', 403 for 'you can't do this'.
What is the difference between 301 and 308?: 301 Moved Permanently may change the method from POST to GET on redirect (historical behavior). 308 Permanent Redirect preserves the method. Use 308 for permanent redirects where the method must not change; 301 for compatibility with older clients.